The functional sequences of control devices, used to control and/or regulate the operational sequences in a motor vehicle, are controlled from an input program using associated data which are input by the customer or the manufacturer of the control device. In its execution, this program is dependent upon the frequency of the CPU of the control device. A common source of error is the implementation of a program that is not set up for the frequency of the CPU. Such a program is unable to run and may also no longer be reprogrammed since the routines for establishing the communication must be located in the frequency-dependent part of the software, thus making communication to the outside impossible. In such a case, the control-device program is no longer accessible from the outside and the control device may need to be returned to the manufacturer. For safety reasons, the execution of an incorrectly programmed program upon start-up of the vehicle should be prevented.
Therefore, there is a need to develop a control device and a method which prevents the execution of an incorrectly programmed program and allows a correction of the faulty program and the starting of such a control device.